X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=util.c;h=18f98dc4f17859e5c5724a8d25ed39271ba89e70;hb=ebb648622191195e3e216c103b83549f97cf28d4;hp=e69de29bb2d1d6434b8b29ae775ad8c2e48c5391;hpb=58936d6ab733acf784cf8b1a8f6839b7a75bfe7a;p=wmpus

diff --git a/util.c b/util.c
index e69de29..18f98dc 100644
--- a/util.c
+++ b/util.c
@@ -0,0 +1,86 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+
+#include "util.h"
+
+list_t *list_insert(list_t *next, void *data)
+{
+	list_t *node = new0(list_t);
+	node->data = data;
+	node->next = next;
+	node->prev = next ? next->prev : NULL;
+	if (node->next) node->next->prev = node;
+	if (node->prev) node->prev->next = node;
+	return node;
+}
+
+void list_insert_after(list_t *prev, void *data)
+{
+	// prev must be valid,
+	// as we cannot return the original list head
+	list_t *node = new0(list_t);
+	node->data = data;
+	node->prev = prev;
+	node->next = prev->next;
+	prev->next = node;
+	if (node->next) node->next->prev = node;
+}
+
+list_t *list_append(list_t *head, void *data)
+{
+	list_t *last = head;
+	while (last && last->next)
+		last = last->next;
+	list_t *node = new0(list_t);
+	node->data = data;
+	node->prev = last;
+	if (last) last->next = node;
+	return last ? head : node;
+}
+
+list_t *list_remove(list_t *head, list_t *node)
+{
+	list_t *next = node->next;
+	list_t *prev = node->prev;
+	if (next) next->prev = prev;
+	if (prev) prev->next = next;
+	free(node);
+	return head == node ? next : head;
+}
+
+int list_length(list_t *node)
+{
+	int len = 0;
+	for (; node; node = node->next)
+		len++;
+	return len;
+}
+
+list_t *list_last(list_t *list)
+{
+	while (list && list->next)
+		list = list->next;
+	return list;
+}
+
+list_t *list_find(list_t *list, void *data)
+{
+	for (list_t *cur = list; cur; cur = cur->next)
+		if (cur->data == data)
+			return cur;
+	return NULL;
+}
+
+/* Misc */
+int error(char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	fprintf(stderr, "Error: ");
+	vfprintf(stderr, fmt, ap);
+	fprintf(stderr, "\n");
+	va_end(ap);
+	exit(1);
+	return 0;
+}